Cranial ultrasound is a reliable first step imaging in children with suspected craniosynostosis.

PURPOSE: Skull radiography (SR) and Computed Tomography (CT) are still proposed as the first-line imaging choice for the diagnosis of craniosynostosis (CS) in children with abnormal head shape, but both techniques expose infants to ionizing radiation. Several studies shown that ultrasound may play an important role in the diagnosis of craniosynostosis. The aim of our study is to assess the diagnostic accuracy of cranial ultrasound scan (CUS) and confirm if it is a reliable first step imaging evaluation for the diagnosis of craniosynostosis in newborn.

METHOD: A cohort of 196 infants (122/74 males/females), with a mean age of 4 months, clinically suspected to have abnormal closure of cranial sutures, were firstly examined by CUS and then referred to neuroradiologists to perform volumetric CT scan if the suspicion of stenosis was ecographically confirmed; otherwise, a routine follow-up and physical treatment was performed, to observe the evolution of the head shape.

RESULTS: Of the 196 children studied by CUS, only two had inconclusive studies due to age limitation (>12 months). Thirty children were diagnosed with cranial synostosis at CUS and verified by CT; all the CUS results were confirmed, except two cases, that were revealed as false positives in the starting phase of the study. Twelve patients with very prominent head deformity and negative CUS underwent CT, which confirmed the CUS results in all of them; one case of closure of both temporal sutures, not studied by CUS, was documented by CT. All the 148 children with poor clinical suspicion and negative CUS underwent just a prolonged clinical follow-up. In all of them, a progressive normalization of head shape was observed, and the craniosynostosis was excluded on a clinical base.

CONCLUSIONS: CUS is a highly specific and sensitive imaging technique. In referral centers, expert hands can use it as a reliable first-step screening for infants younger than 1 year, suspected to have a craniosynostosis, thus avoiding unnecessary exposure to ionizing radiation. The "golden age" to obtain the best CUS results is under 6 months of life. Because the method is operator-dependent and there is a learning curve, a case centralization is advisable.